Realization of a high-accuracy detection
system between electric wheelchairs
and the moving object on the
community road
06/03/2015
NTT DOCOMO, INC
Smart-life Solutions Department
Hisakazu Tsuboya
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１．Background
In Japan, “aging society with fewer children progresses”, more than 65-year-old elderly, in
the next five years is forecast to increase by 6.4%, in the next decade is predicted to 8.5%.
Highly usage of mobility supports, for instance wheelchairs and senior cart, shall increase any
traffic accidents.
Remote control and management technologies enhanced by mobile network are expected to
restrain and reduce any conflicts between those mobility supports.
Fig.1) Age-specific population estimates of Japan
Fig.3) Trends in the number of traffic accidents
Population (hundred)
Source ：Cabinet Office
2012 edition aging society White Paper
Fig.2) Cumulative shipments of electric wheelchair
Source ：Tokyo Metropolitan Police Department
Traffic Bureau report
Fig.4) Trends in the number of wheelchair accident
Cumulative shipments
Source ：Electric wheelchairs Safety Association HP
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Source ： National Police Agency report
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2．Solutions for reducing accidents
In traffic accidents, “cognitive delay and mistake” occupied 70% of the causes.※) It can be
understood that decline in cognitive abilities of the elderly people would have sever influences.
On the other hand, being able to notify in advance danger, the accidents will be reduced.
Considering the recent mobile technology innovations, we investigate the detection system with
mobile remote sensing functions detects the degree of proximity between the moving object.
③Detection of
approaching
④caution
⑤Alarm sounds
②transmit of the
Position
information and
approach
information
④caution
⑤Alarm sounds
①approach
※) Source：2001 ITARDA report
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3．Technology approach
※)
Electric wheelchair accident occurs on a community road. Therefore, even if shield or view is
blocked, it is necessary to be able to confirm the relative positions and to be able to detect the
moving object.
So, we have established a detection system by measuring using GPS and field intensity.
※) Source：National Police Agency report
Image processing and radar waves has been
implemented in the automotive, that is not
good at the environment that wall and
complex buildings housing is gather in the
near.
Even if shield, it is necessary to be able to
confirm the relative positions.
measuring
using GPS
We have established a detection
system by measuring using GPS and
field intensity.
measuring using
field intensity
Obstacles such as fence
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© 2008 NTT DOCOMO, INC. All rights reserved.
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4．Goals and planning
・Research goal
: To confine a positioning error of a moving objects within 1m.
Give a caution to take action avoiding before 3 seconds.
（Set the appropriate number of seconds in the study）
・Outcome
: We reduce the electric wheelchair-related traffic accidents
will increase, and contribute to welfare.
・Commercialization plan : We consider providing an optional service to ensure the safety,
②
③
⑤
④
①
<2014 fiscal year＞
■To build a detection system between moving
objects and to build a detection system with
network information
①Measuring the relative position using
field intensity
②Measuring the absolute position using GPS
and quasi-zenith satellite
③Development of server system
（Implementation of data storage function）
■Collect the data by the basic experiment
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＜ 2015 fiscal year＞
■To build an approach detection system
④Implementation of the position
calculation technology
⑤Implementation of the notification
technology
■Improvement of a detection system
between moving objects
■Set the appropriate number of seconds
to take action avoiding
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＜ 2016 fiscal year＞
■Improvement for practical use
・The calculation and evaluation
experiment of the position
information
・Measurement experiments in
crowded environment
・Collection of big data
・Study of a method for analyzing
big data
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5．2014 Fiscal Research
This year, we constructed a detection system between moving objects and a
detection system with network information. And We collected data by basic
experiments.
【Test-1】 Measurement of characteristics
purpose ：Confirmation of a radio wave characteristics
due to the receive direction and distance
【Test-3】Detection test : moving - moving
purpose ：Accuracy check of proximity detection using
BluetoothLE in the case of electric wheelchair and
pedestrian move together
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【Test-2】Detection test : static - moving
purpose ： Accuracy check of proximity detection using
BluetoothLE in the case of one of the electric wheelchair
or walker (or both) is static
【Test-4】Detection test with NW information
purpose ： Accuracy check of measuring the electric
wheelchair position using GPS + quasi-zenith satellite
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Please see the presentation slide
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© 2008 NTT DOCOMO, INC. All rights reserved.
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６．Consideration
Please see the presentation slide
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7．2015 Fiscal Research
The next fiscal year, we will (1)improve the basic technology that
was developed this year, and implement (2) the position calculation
technology and (3)the notification technology to the server.
At the same time, we I consider how many seconds / meters we
should notify before.
Also at this time, we narrow the accident case of electric wheelchair.
Not only pedestrian, and also consider bicycle and automobile
running in the alley at a low speed as an accident case.(4)
(2) the position calculation technology
(3) the notification technology
(1) Improvement of basic technology
(1)
(4)expansion of the scope
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